In the prior art, there have been linear motion devices which are composed of a rail element and a linearly moving element, and which comprise endless rolling element circulation paths configured from load paths provided between the rail element and the linearly moving element, no-load paths provided to the linearly moving element, and return paths that link the load paths and the no-load paths together, the rail element and the linearly moving element moving reciprocatingly and linearly relative to each other.